Circuit breaker mounting assembly including means for temporarily supporting the circuit breaker during initial securement



Filed Oct. 25, 1965 Au yl. 1967 CIRCUIT BREAKER MOUNTING ASSEMBLYINCLUDING M OR TEMPORARILY SUPPORTING THE CIRCUIT BREAKER DURING INITIALSECUREMENT A. STROBEL EANS 5 Sheets-Sheet l MEAN 5 Sheets-Sheet 2 IQ m?6 A. STROBEL MOUNTING ASSEMBLY INCLUDING FOR TEMPORARILY SUPPORTING THECIRCUIT BREAKER DURING INITIAL SECUREMENT -7/P/PP50 Aug. 1, 196701110011 BREAKER Filed Oct- 25, 1965 Aug. 1, 1967 A. STROBEL. 3,334,277CIRCUIT BREAKER MOUNTING ASSEMBLY INCLUDING MEANS FOR TEMPORARILYSUPPORTING THE CIRCUIT V BREAKER DURING INITIAL SECUREMENT Filed Oct.25, 1965 3 Sheets-Sheet 5 nite Stats ate ABSTRACT OF THE DISCLOSURE Acircuit breaker mounting assembly for mechanically supporting thebreaker and providing the electrical connection to the externalcircuitry, which further includes provision for temporarily supportingthe weight of the breaker during initial securement.

My invention relates to a novel mounting assembly for receiving acircuit breaker unit, and more particularly to such a mounting assemblywhich includes electrical bus of a suitable configuration to temporarilysupport the weight of the circuit breaker during the initial stages ofsecurement.

Molded case circuit breakers of the larger frame sizes, as for example,of the type which is the subject of copending US. patent applicationentitled, Circuit Breaker Contact Mounting, filed Feb. 5, 1965, Ser. No.430,549, now US. Patent No. 3,268,702, in the name of Carl E. Gryctko,and assigned to the assignee of the instant invention, are oftentimesquite heavy. Typically, such units may weighbetween 25 and 50 pounds,and sometimes even in excess of 100 pounds. Such units are usuallymounted to their associated enclosure, panel board or other mountingstructure in a generally vertical orientation. Hence, during the initialstages of circuit breaker securement it becomes necessary to provide ameans for supporting the circuit breaker unit prior to the actualbolting of the unit to the associated support structure. In the pastthis has required two persons; one to hold the breaker and the other tomake the necessary connections. This problem has been eased somewhat bythe provision of additional ledge like protrusions on the mountingstructure onto which the breaker is positioned while the mounting boltsare inserted and tightened, so as to avoid the need for additionalpersonnel. These prior art support ledges were typically eitheradditional or integral parts of the insulative mounting blocks orstructural mounting members. Hence, their use has required additionalmaterial, and/or additional operations and space, thereby adding to thecost, size and complexity of the mounting structure.

In my invention, the need for such additional material or parts isavoided by forming the electrical bus work itself of suitableconfiguration to provide temporary support of the breaker during itsinitial placement against the mounting structure. More specifically, thebus work which interconnects the circuit breaker terminals to theexternal circuit includes a first portion which is secured to aninsulative base support member and a second portion which is of asuitable configuration for mechanical and electrical securement to thecircuit breaker terminal. The second portion includes a Substantialcross-sectional area of conductive material which freely projects out-Ward from the base support and is shaped to cooperatively enter areentrant recess of the circuit breaker housing. When the circuitbreaker is initially placed on the support structure, these forwardlyprojecting porfree tions of the individual terminal connectors abut asufficient depthand area of the circuit breaker housing wall surfacesabout their respective terminal openings, to provide suitable support ofthe circuit breaker prior to the actual bolting thereof to such supportstructure.

This support is at least provided at the uppermost end of the breaker,but may advantageously be employed at both the line and load ends foradditional support, as well as symmetry of support structure. Further,where a multi-phase circuit breaker unit is to be received, the adjacentconnector means forwardly projecting support portions are laterallyspaced an amount corresponding to the adjacent pole spacing of thecircuit breaker terminals.

Hence, I provide a suitable, cooperative configuration of the circuitbreaker terminal connector means and housing opening, such that thesupport of the breaker is provided within the confines of the breakerhousing with the connector that is employed to carry the line and/orload current between the circuit breaker terminals and externalcircuitry. This advantageously avoids the prior art utilization ofadditional ledges or other projecting members for temporarily supportinga circuit breaker during the initial securement thereof.

It is therefore seen that a principal object of my invention is toprovide an improved circuit breaker mountin-g structure.

A further object of my invention is to provide a circuit breakermounting arrangement wherein temporary support of the circuit breaker,prior to bolting thereof to the support structure, is provided by asuitable configuration of the electrically conductive connector means.

Another object of my invention is to provide a temporary means forsupporting a circuit breaker, in a generally vertical orientation, whichincludes the cooperative engagement of a substantial cross-sectionalarea of the terminal connector conductive material in conjunction with asimilarly cross-sectioned reentrant opening of the circuit breakerhousing about its terminal connector.

An additional object of my invention is to provide a mounting supportarrangement for receiving a multiphase circuit breaker unit wherein atleast some of the individual terminals thereof are recessed within areentrant housing opening, of a suitable configuration to mate with aforwardly projecting portion of the support structure connector means,such that abutment of the connector means forwardly projecting portionagainst the wall surface of the circuit breaker housing reentrantopenings will provide temporary support of the circuit breaker unitprior to the bolt mounting thereof to the support structure.

These as well as other objects of my invention will readily becomeapparent upon consideration of the following description and drawings inwhich:

FIGURE 1 is an exploded perspective view showing the manner in which atypical multiphase circuit breaker unit may be mounted to the supportstructure in accordance with the novel concepts of the invention.

FIGURE 2 is a perspective view partially cut away showing the manner inwhich the circuit breaker unit is initially supported in accordance withmy invention.

FIGURE 3 is a longitudinal view partially in crosssection of the mountedcircuit breaker, showing the manner in which the mating engagement ofthe support structure connector means and circuit breaker housing aboutits respective terminals provides support of the breaker in accordancewith the novel concept herein disclosed.

FIGURE 4 is a plan view showing the manner in which the circuit breakerunit is positioned and supported in accordance with my invention.

Referring to the figures, circuit breaker unit which is adapted to besupported in accordance with the instant invention is shown as athree-pole unit constructed in the manner more fully discussed inaforementioned US. Patent No. 3,268,702. It should, however, berecognized that the particular circuit breaker unit shown is only forillustrative purposes and the novel concept of the instant invention maybe utilized in conjunction with numerous other circuit breaker designsof the single or multipole variety, with, however, its most advantageousaspects being achieved where such units are of a substantial weight.Such a unit 10, which may typically be designed to have a continuouscurrent rating of 1600 amps and an interrupting rating of 75,000 amperesat 600 volts, requires substantial and rugged current carrying membersand operating components. Such substantial members, as well as thesturdily constructed housing 12 of the unit, constructed to safelywithstand the mechanical and thermal shock loading to which it is to besubjected, increase the overall circuit breaker weight, such thatbreakers of the frame size oftentimes weigh in the order of 50 poundsand sometimes over 100 pounds.

Circuit breaker unit 10 is generally enclosed within a housing 12 havinglaterally adjacent compartments, generally indicated as 13, 14 and 15for the respective phase components. The center phase 14 includes anoperating mechanism generally shown as 16 which operates in thewell-known conventional manner to automatically trip the circuit breakerresponsive to the sensing of an overload condition by trip unit assembly20, as well as operating handle 18 for manual opening or closing of thecircuit breaker unit 10. For the sake of brevity, the operation thereofwill not be discussed. However, reference is made to U.S. Patent No.3,268,702. for a fully detailed description. The circuit breakerincludes individual pole, line terminal conducting straps indicated as25-A, 25-B and 25-C, respectively, as well as corresponding loadterminal conducting straps 35A, 35B and 35C at the opposite end of thecircuit breaker housing.

Circuit breaker 10 is illustratively shown as mounted to an enclosuregenerally indicated as 26. Enclosure 26 includes upstanding anglemembers 27 and laterally extending transverse support angle members 28,30, 32, 34, respectively, which angle members have bolted thereto (as bybolts 35) a pair of support assemblies generally shown as 40, which areof the type described and claimed in copending US. patent applicationentitled Circuit Breaker Mounting Arrangement, filed on even dateherewith, Ser. No. 503,185, in the name of John C. Brumfield, andassigned to the assignee of the instant invention. Although such supportassemblies 40 are shown to demonstrate the novel concepts of the instantinvention, it should be understood that this is done for illustrativepurposes only, with the broad aspects of the support arrangement of myinvention being likewise adaptable to other circuit breaker mountingsupport structures.

Support assembly 40 includes an insulative housing support 44, dividedinto laterally adjacent compartments, with an individual conductivestrap 42, corresponding to each of the line and load terminals of thecircuit breaker to be received, being located within each compartment.Conducting strap 42 is appropriately mounted to the insulative housing44 as by bolt means 45. Conducting strap 42 includes a portion 47,adapted to receive the external circuit connections. These may bedirectly bolted to openings 49 thereof, as shown by line bus 75, or anintermediate cable conductor 51 may be used of the type which is thesubject of copending U.S. patent application Ser. No. 503,320, filed oneven date herewith, in the name of John R. Chamberlin, Jr., entitledReversible Connector Arrangement, and assigned to the assignee of theinstant invention, for connecting the load end to cables 52.

In accordance with my invention, a reentrant opening is located at theunderside of the circuit breaker housing, inwardly extending from thebottom surface of circuit breaker housing 12 to the location of itsrespective terminal conducting strap, As for example, openings 27A, 27Band 27C are located immediately adjacent their respective line terminalstraps 25A through 25C, respectively; and similar openings 29A, 29B and29C are located immediately adjacent the load terminal conducting straps35A through 35C, respectively. These reentrant openings are of apredetermined configuration, illustratively shown as partially circularcircumferential region 30 joined by a flat region 32 to complete theperimeter thereof.

The individual terminal conducting strap 42 includes a further portion50 which freely projects outward from the base 44 of the supportstructure and is of substantial cross-sectional area with an outerperipheral wall of a suitable configuration and depth to abutingly matewith and be received within the respective housing reentrant openings 27and 29. It should be naturally recognized that the lateral spacingbetween forwardly projecting portions 50 of the adjacent terminal strap42 corresponds to the lateral spacing between the respective circuitbreaker line and load terminals (e.g. 25A, 25B, 25C; 35A, 35B, 35C),such that the forwardly projecting portions 50 are simultaneouslylocated within their respective reentrant openings 27A, 27B, 27C or 29A,29B, 29C about the adjacent circuit breaker line or load terminals. Theforward portion 50 of the connector means 42 also includes tappedopenings 54 which are suitably located to mate with clearance openings55 of the circuit breaker terminal conducting straps 25, 35, such thatfirm, mechanical and electrical securement of the circuit breakerterminal to their respective strap forward portion 50 is achieved bybolts 60 in conjunction with flat washer 62 and lock washer 64, suchthat the substantial cross-sectional areas of forwardly projectingportions 50 are drawn into closely confronting engagement with theirrespective circuit breakertermiuals 25, 35. This provides an intimateelectrical connection of the type required for larger frame sizebreakers designed to handle appreciable currents. Also the mountingsupport base means 40 includes laterally spaced threaded inserts 65which mate with mounting openings 67 of the circuit breaker unit 10,such that the circuit breaker unit may be rigidly mounted to theinsulative support means 40 by the provision of fastening bolt 66, flatwasher 68 and lock washer 70.

In accordance with my invention, during the initial placement of thecircuit breaker unit 10 to line and load support assemblies 40, it willbe noted that forward portions 50 of the respective conducting straps 42enter their associated reentrant openings 27A, 27B, 27C and 29A, 29B,29C, such that the peripheral portions of the forwardly projectingconductive sections 50 abut the adjacent wall surfaces of theirrespective circuit breaker reentrant housing openings in a mannerproviding suitable support of the circuit breaker unit 10. Thisadvantageously avoids the need for additional mounting ledges or otherprojecting portions, or the requirement of additional personnel to holdthe circuit breaker prior to the actual bolting thereof. As for example,note in FIGURES 2 and 3 the manner in which the forwardly projectingportion 50 of the conducting strap 42 is abuttingly resting on theadjacent Wall surface of the housing reentrant opening 27A. It should besimilarly recognized that the forwardly projecting substantialcross-sectional portion 50 of the adjacent pole conducting means 42similarly extend into reentrant openings 27B, 27C and abut the wallsurfaces about such reentrant openings for supporting and positioningthe circuit breaker unit. Advantageously, such support is also providedat the lower orientated load end of the breaker by the terminalengagement of load connector means 50 and the wall surfaces of housingopenings 29A, 29B and 29C. Hence, with the circuit breaker resting onsuch integrally formed forwardly projecting portions 50 of the externalcircuit bus, the circuit breaker may then be bolted to the supportstructure as by the provision of bolt 66 and associated lock Washer andflat washer, with the individual terminals then being electricallyconnected to the individual terminal straps as by the provision of bolt60 and its associated flat washer and lock washer.

It is therefore seen that my invention achieves a substantialsimplification in a manner in which a circuit breaker of a substantialweight is supported prior to the bolting to its mounting supportstructure, with such simplification arising by suitably shaping theexternal circuit conducting means to cooperatively enter a housingrecess, such that the support thereof does not require any extra partsor assemblies and is completely confined within the volume of thecircuit breaker housing.

Although there has been described a preferred embodiment of this novelinvention, many variations and modifications will now be apparent tothose skilled in the art. Therefore, this invention is to be limited,not by the specific disclosure herein, but only by the appending claims.

The embodiments of the invention in which an exclusive privilege orproperty is claimed are defined as follows:

1. A mounting assembly for receiving at least one circuit breaker unit,said mounting assembly comprising a base support member and at least oneelectrically conductive connector, said connector including integrallyformed first and second portions, said conductive connector secured tosaid base support member, said second portion adapted to providemechanical and electrical securement to a circuit breaker terminal, saidsecond portion freely projecting outward from said base support memberand including a substantial cross-sectional area of conductive material,the internal region of said cross-sectional area including aperturemeans for receiving at least one connecting bolt, such that saidsubstantial cross-sectional area is drawn into confronting engagementwith the circuit breaker terminal, said freely projecting portion aboutsaid aperture means having an outer peripheral wall of a predeterminedconfiguration closely corresponding to a recess of a circuit breaker,about the circuit breaker terminal, said outer peripheral wall having apredetermined depth selected to abut wall surfaces of the circuitbreaker recess in a manner providing support of the circuit breakerduring bolted securement of its terminals to said first portion.

2. A mounting assembly for receiving at least one circuit breaker unit,and mounting said circuit breaker unit in a generally verticalorientation, a base support member and at least one electricallyconductive connector, said connector including integrally formed firstand second portions, said conductive connector secured to said basesupport member, said second portion adapted to provide mechanical andelectrical securement to a circuit breaker terminal, said second portionfreely projecting outward from said base support member in a generallyhorizontal direction, and including a substantial cross-sectional areaof conductive material, the internal region of said cross-sectional areaincluding aperture means for receiving at least one connecting bolt,such that said substantial cross-sectional area is drawn intoconfronting engagement with the circuit breaker terminal, said freelyprojecting portion about said aperture means having an outer peripheralWall of a predetermined configuration closely corresponding to a recessof a circuit breaker, about the circuit breaker terminal, said outerperipheral wall having a predetermined depth selected to abut wallsurfaces of the circuit breaker recess in a manner providing support ofthe circuit breaker during bolted securement of its terminals to saidfirst portion.

3. A mounting assembly for receiving a multi-phase circuit breaker unitand mounting said circuit breaker unit in a generally verticalorientation, said mounting assembly comprising insulative base supportmeans and an individual electrically conductive connector means for eachof the circuit breaker phases, rigidly mounted thereto, said connectormeans including integrally formed first and second portions, said firstportion including means for mechanical securement to said base supportmeans, said second portion including means for mechanical and electricalsecurement to its respective circuit breaker terminal, said secondportion freely projecting outward from said base support member in agenerally horizontal direction, and including a substantialcross-sectional area of conductive material, the internal region of saidcross-sectional area including aperture means for receiving at least oneconnecting bolt, such that said substantial cross-sectional area isdrawn into confronting engagement wtih the circuit breaker terminal,said freely projecting portion about said aperture means having an outerperipheral Wall of a predetermined configuration closely correspondingto a recess of a circuit breaker, about the circuit breaker terminal,said outer peripheral wall having a predetermined depth selected to abutwall surfaces of the circuit breaker recess in a manner providingsupport of the circuit breaker during bolted securement of its terminalsto said first portion.

4. In combination, a circuit breaker unit and a mounting assemblytherefor, said circuit breaker including a housing, having line terminalmeans at one end thereof, and load terminal means at the other endthereof, said housing including a reentrant opening about the individualterminal means, including an inner wall region substantially containedwithin the volume defined by said housing, said mounting assemblycomprising an insulative base support means and individual electricallyconductive connector means positioned to mate with said circuit breakerline and load terminal means, said connector means including integrallyformed first and second portions, said first portion including means formechanical securement to said base support means, said second portionincluding means for mechanical and electrical securement to itsrespective circuit breaker terminal, said second portion freelyprojecting outward from said base support means and including asubstantial cross-sectional area of conductive material, thecross-sectional area of said freely projecting portion having aconfiguration closing conforming to the cross-sectional area of thereentrant opening about its respective circuit breaker terminal, saidforwardly projecting portions abutting the wall surfaces of theirrespective reentrant openings in a manner providing support of thecircuit breaker during securement of its terminals to said firstportions.

5. In combination, a circuit breaker unit and a mounting assemblytherefor, said circuit breaker including a housing, having line terminalmeans at one end thereof, and load terminal means at the other endthereof, said housing including a reentrant opening about at least someof the individual terminal means, including an inner wall regionsubstantially contained within the volume defined by said housing, saidmounting assembly comprising an insulative base support means andindividual electrically conductive connector means positioned to matewith said circuit breaker line and load terminal means, said con nectormeans including integrally formed first and second portions, said firstportion including means for mechanical securement to said base supportmeans, said second portion including means for mechanical and electricalsecurement to its respective circuit breaker terminal, the secondportion of those connector means for securement to the circuit breakerterminals having associated reentrant openings, freely projectingoutward from said base support means and including a substantialcross-sectional area of predetermined configuration, the cross-sectionalarea of said freely projecting portion having a configuration closelyconforming to the cross-sectional area of the reentrant opening abouttis respective circuit breaker terminal, said forwardly projectingportions abutting the wall surfaces of their respective reentrantopenings in a manner providing support of the circuit breaker duringsecurement of its terminals to said first portions.

6. In combination, a circuit breaker unit and a mounting assemblytherefor, for mounting said circuit breaker unit in a generally verticalorientation, said circuit breaker including a housing, having lineterminal means at one 7 end thereof, and load terminal means at theother end thereof, said housing including a reentrant opening about atleast some of the individual terminal means, including an inner,generally horizontally extending, Wall region substantially containedwithin the volume defined by said housing, said mounting assemblycomprising an insulative base support means and individual electricallyconductive connector means positioned to mate with said circuit breakerline and load terminal means, said connector means including integrallyformed first and second portions, said first portion including means formechanical securement to said base support means, said second por tionincluding means for mechanical and electrical securement to itsrespective circuit breaker terminal, the second portions of thoseconnector means for securement to the circuit breaker terminals havingassociated reentrant openings, freely projecting outward from said basesupport means in a generally horizontal direction, and including asubstantial cross-sectional area of predetermined configuration, thecross-sectional area of said freely projecting portion having aconfiguration closely conforming to the cross-sectional area of thereentrant opening about its respective circuit breaker terminal, saidforwardly projecting portions abutting the wall surfaces of theirrespective reentrant openings in a manner providing support of thecircuit breaker during securement of its terminals to said firstportions, and said circuit breaker is in its generally verticalorientation.

7. The combination as set forth in claim 6, wherein said circuit breakerweighs at least in the order of fifty pounds.

8. The circuit breaker unit and mounting assembly therefor, as set forthin claim 6, said circuit breaker weighs in excess of twenty-five pounds.

9. A mounting assembly as set forth in claim 2, wherein said freelyprojecting portion when received within said circuit breaker recess isadapted to support a circuit breaker in excess of twenty-five pounds.

10. In combination, a three-phase circuit breaker unit and a mountingassembly therefor for mounting said circuit breaker in a generallyvertical orientation, said circuit breaker including a housing, havingfirst, second and third line terminal means at one end thereof, andfirst, second and third load terminal means at the other end thereof,said housing including a reentrant opening about the individual terminalmeans, including an inner generally horizontally extending wall regionsubstantially contained within the volume defined by said housing, saidmounting assembly comprising an insulative base support means andindividual electrically conductive connector means positioned to matewith said circuit breaker line and load terminal means, each of saidconnector means including m tegrally formed first and second portions,said first portion including means for mechanical securement to saidbase support means, said second portion including means for mechanicaland electrical securement to its respective circuit breaker terminal,said second portions freely projecting outward from said base supportmeans in a generally horizontal direction and including a substantialcross-sectional area of predetermined configuration, the cross-sectionalarea of said freely projecting portion having a configuration closelyconforming to the cross-sectional area or the reentrant opening aboutits respective circuit breaker terminal, said forwardly projectingportions abutting the wall surfaces of their respective reentrantopenings in a manner providing support of the circuit breaker duringsecurement of its terminals to said first portions, and said circuitbreaker is in its generally vertical orientation.

References Cited UNITED STATES PATENTS 2,441,485 5/1948 Graves et a1.317-119 2,930,020 3/1960 Powell 3l7l 19 3,150,290 9/1964 Edmunds 3171l9ROBERT K. SCHAEFER, Primary Examiner.

H. O. JONE S, Assistant Examiner.

1. A MOUNTING ASSEMBLY FOR RECEIVING AT LEAST ONE CIRCUIT BREAKER UNIT,SAID MOUNTING ASSEMBLY COMPRISING A BASE SUPPORT MEMBER AND AT LEAST ONEELECTRICALLY CONDUCTIVE CONNECTOR, SAID CONNECTOR INCLUDING INTEGRALLYFORMED FIRST AND SECOND PORTIONS, SAID CONDUCTIVE CONNECTOR SECURED TOSAID BASE SUPPORT MEMBER, SAID SECOND PORTION ADAPTED TO PROVIDEMECHANICAL AND ELECTRICAL SECUREMENT TO A CIRCUIT BREAKER TERMINAL, SAIDSECOND PORTION FREELY PROJECTING OUTWARD FROM SAID BASE SUPPORT MEMBERAND INCLUDING A SUBSTANTIAL CROSS-SECTIONAL AREA OF CONDUCTIVE MATERIAL,THE INTERNAL REGION OF SAID CROSS-SECTIONAL AREA INCLUDING APERTUREMEANS FOR RECEIVING AT LEAST ONE CONNECTING BOLT, SUCH THAT SAIDSUBSTANTIAL CROSS-SECTIONAL AREA IS DRAWN INTO CONFRONTING ENGAGEMENTWITH THE CIRCUIT BREAKER TERMINAL, SAID FREELY PROJECTING PORTION ABOUTSAID APERTURE MEANS HAVING AN OUTER PERIPHERAL WALL OF A PREDETERMINEDCONFIGURATION CLOSELY CORRESPONDING TO A RECESS OF A CIRCUIT BREAKER,ABOUT THE CIRCUIT BREAKER TERMINAL, SAID OUTER PERIPHERAL WALL HAVING APREDETERMINED DEPTH SELECTED TO ABUT WALL SURFACES OF THE CIRCUITBREAKER RECESS ING A MANNER PROVIDING SUPPORT OF THE CIRCUIT BREAKERDURING BOLTED SECUREMENT OF ITS TERMINALS TO SAID FIRST PORTION.